1. Field of the Invention
The present invention relates to a head protecting airbag device to be mounted on a vehicle. More specifically, the invention relates to a head protecting airbag device, in which an inlet port of an airbag to be connected to a gas feeder member for feeding inflating gas is positioned above an intermediate pillar portion arranged between a front pillar portion and a rear pillar portion of the vehicle.
2. Description of the Related Art
A head protecting airbag device of this kind is disclosed in DE 20105734 U1. In this head protecting airbag device, an inlet port for introducing the inflating gas downward into the airbag is arranged above the portion in the airbag midway in the longitudinal direction of the vehicle so as to admit the inflating gas downward into the airbag.
To this inlet port of the airbag, moreover, there is connected a gas feeder member for feeding the inflating gas. This gas feeder member consists of an inflator for generating the inflating gas and a feed pipe joined to the inflator. The gas feeder member has rigidity, it being a rod-shaped member arranged in the longitudinal direction of the vehicle. In the vicinity of one end of the gas feeder member, there are arranged gas discharge ports for discharging the inflating gas. These gas discharge ports are so opened in the lower face side of the gas feeder member as to discharge the inflating gas downward.
However, the head protecting airbag device of the aforementioned construction has the following problems when the inlet port of the airbag is arranged above the intermediate pillar portion arranged between the front pillar portion and the rear pillar portion of the vehicle.
In the airbag, more specifically, a plurality of mounting portions for mounting the airbag on the vehicular body have to be arranged near the upper edge of the airbag at the time when the airbag is completely inflated. Especially, a mounting portion has to be arranged close to the inlet port so that the vicinity of the inlet port will not greatly vibrate or come out when the airbag admits the inflating gas (“vicinity mounting portion”).
During the actual operation of the head protecting airbag device, however, an impact may be applied to the side face of the vehicle. When a collision load is applied to the side face of the intermediate pillar portion so that this intermediate pillar portion is largely displaced toward the interior, moreover, the vicinity mounting portion mounting the vicinity of the inlet port of the airbag on the body and the gas discharge ports of the gas feeder member may deviate away from each other one to the interior side and the other to the exterior side. In this case, the inlet port itself may close the gas discharge ports and interrupt the smooth expansion and inflation of the airbag.
On the other hand, the airbag to be used in the head protecting airbag device of the aforementioned construction has a construction as disclosed in JP-A-2001-233153. This airbag is constructed by hollow-weaving, and the outer peripheral edge portion to be arranged on the outer circumference of the gas receiving portion is by 3×3 diagonal weave.
In the airbag thus disclosed, however, the outer peripheral edge portion is wholly 3×3 diagonally woven. In other words, no consideration has been taken of the portion of the outer peripheral edge portion in which stress concentration easily occurs when the airbag is inflated, such as an inner corner portion which is recessed to receive tension in the expanding direction when the airbag is inflated. In case the inflator used has a high output capacity, therefore, stress may concentrate at the inner corner portion at the time of inflating the airbag, and the airbag may be damaged.